1. Field of the Invention
This invention relates to the oxidation of finely divided metal concentrates by injecting them into a heated enclosure in a flow of air and oxygen.
2. Prior Art
It is known to smelt sulfide ores of copper and lead by injecting the finely divided ore downward into a furnace with air as disclosed in U.S. Pat. No. 1,888,164. It is also known to inject the ores downward into the furnace through a tube concentrically mounted inside an outer tube carrying pressurized oxygen gas as taught by U.S. Pat. No. 3,459,415. In this latter arrangement, the discharge end of the central ore carrying tube extends axially partially into a nozzle mounted on the end of the outer tube. The flow of pressurized oxygen through the nozzle in the outer tube draws the ore concentrate from the inner tube.
U.S. Pat. No. 1,073,462 discloses a burner for making sublimed white lead having three concentric pipes each with a nozzle at the end thereof. Ore concentrates, together with air, are introduced into the inner tube. A rotating rifle grooved spindle swirls the mixture of air and ore concentrates as it is directed toward the nozzle of the intermediate tube. A gaseous fuel introduced through the intermediate tube and air introduced through the outer tube produce a flame which establishes the conditions necessary for the oxidation of the ore concentrates.
One difficulty with the prior art burners used with these ore conversion processes is that splatterings from the furnace can plug the end of the burner and raise the danger that the flaming gases will backup through the ore concentrate supply line and cause fire or severe damage.
It is a primary object of the present invention to provide a burner for use in the flash oxidation of ore concentrates which minimizes the possibility of flashback through the ore concentrate line.
It is also a primary object of the invention to provide such a burner which is efficient, economical and reliable.
It is another object of the invention to provide such a burner which minimizes the amount of high pressure oxygen required to carry out the flash oxidation process.